Printing press



W. A. WHITEHEAD PRINTING PRESS ATTOR/VEY 1947' w. A. WHITEHEAD 2,425,167

PRINTING PRESS Filed June .11, 1943 14 Sheets-Sheet 2 IRE-EA flan QINVZ r02;- 7

Aug. 5, 1947- w. A. WHITEHEAD 2,425,167

PRINTING PRESS Filed June 11, 1943 14 Sheets-Sheet s A TTOR/Vf Y Aug. 5, 1947. w. A. WHITEHEAD PRINTING PRESS Filed June 11, 1943 14 Sheets-Sheet 4 1947- w. A. WHITEHEAD 2,425,167

. PRINTING PRESS Filed June 11, 1943 14 Sheets-Sheet 5 Tran-i A INVENTOR! ATTORNFY Aug. 5, 1947. w. A. WHITEHEAD PRINTING PRESS Filed June 11. 1943 14 Sheets-Sheet 6 TEETA B Aug. 5, 1947- w. A. WHITEHEAD PRINTING PRESS.

14 Sheets-Sheet 7 Filed June 11, 1943 Aug. 5, 1947. w. A. WHXTEHEAD PRINTING PRESS 14 Sheets-Sheet 9 Filed June 11, 1943 INVENTO A 7' TOR/VF Y l4 Sheets-Sheet 10 W. A. WHITEHEAD PRINTING PRESS Filed June 11, 1943 Aug. 5, 1947.

. INVENTGR.

w. A. WHITEHEAD 2,425,167

PRINTING PRESS Aug. 5, 1947.

Filed June 11, 1945 14 Sheets-Sheet ll w. A. WHITEHEAD 2,425,167

PRINTING PRESS Filed June 11, 1943 Aug. 5, 1947.

14 Sheets-Sheet l2 k ygggm i E;

L WMQWETJ MAM ATTORNEY g- 1947- w. A. WHITEHEAD 2,425,167

PRINTING PRESS Filed June 11 1943 14 Sheets-Sheet 13 INVENTOR.

JKRQ WMQ ATTOR/VFY Aug. 5, 1947.

W. A. WHITEHEAD PRINTING PRESS Filed June 11, 1943 l4 Sheets-Sheet l4 ATTORNEY Patented Aug. 5, 1947 PRINTING PRESS William Arnold Whitehead, Preston, England, as-

signor to The Goss Printing Press Company, Chicago, Ill., a corporation of Illinois Application June 11, 1943, Serial No. 490,459 In Great Britain July 2, 1942 11 Claims.

This invention relates to improvementsinprinting presses and refers more particularly to nonstop" printing mechanism such as is commonly employed for printing late news or like matter.

It is an object of this invention to provide a non-stop printing mechanism which is entirely automatic in operation and which is independent of the skill of the operator.

Another object of the invention resides in the provision of a mechanism of the class referred to in which the type matter will be properly inked before impression.

It is a further object of the invention to reduce to a minimum the number of copies spoilt by a change in the matter printed by the nonstop mechanism.

' A still further object of the invention resides in the provision of a .non-stop printing mechanism in which the minimum of operating gear is required.

Still another object of the invention is to enable type plates ofiull or partial circumferential length to be employed.

Other objects of the invention and advantages thereof will be clear from the following description of a preferred embodiment thereof, reference being made therein to the annexed drawings.

In said drawings:

Figure 1 is a diagrammatic end elevation of a perfecting rotary printing press embodying a non-stop" printing unit fitted with a single impression cylinder assembly;

Figures 2a and 2b jointly show'partly in section and partly in plan a non-stop" printing unit having a single impression cylinder, and the mechanism for driving said cylinder and the type cylinder;

Figure 2c shows views of two of the gears of the speed synchronizing gearing;

Figure 3 is a rear end elevation of Figure 2a;

Figures 4a and 4b jointly show in side elevation the mechanism for moving the impression cylinder laterally into engagement with the respective type cylinders;

Figure 5 is a rear end elevation of Figure 4a;

Figure 6 is a detail section showing a part of the timing gearing and the associated synchronizing paw] and ratchet mechanism;

Figure 7 is a diagram of theelectrical equipment and connections for the "non-stop printing unit shown in Figures 2 to 5;

Figure 8 is a detail plan view showing a modification of the mechanism for supporting and laterally moving the impression cylinder;

Figure 9 is a sectional view on line IX-lX of Fig. 8;

Figure 10 is 'a detail section showing a modified arrangement of'switch gear for controlling lateral movement of the impression cylinder assembly;

Figure 11 is a. plan view of a portion of a nonstop" printing unit having an impression cylinder assembly comprising two cylinders; and

Figure 12 is an end partly in section elevation of Figure 11.

To provide for changes being made in the matter printed on the paper web, it has hitherto been customary to employ a non-stop printing mechanism comprising an impression cylinder and two sets of type cylinders, one of said sets running in contact with the impression cylinder "and" the other being stationary and out of contact with said cylinder. To change-the printed matter, the required printing plates are inserted by the operator on the stationary set of type cylinders, which are then set in rotation and are brought upto nearly the surface speed of the web. When the type matter is registered in the correct cir- 'cumferential position in relation to the paper web,- this set of type cylinders is moved into direct drive connection with the impression cylinder to print the new or added matter on the web, the other or superseded set of type cylinders being disengaged from the impression cylinder drive so that they come to rest in readiness to receive other printing plates having further changed or added matter th'ereon.

There are in general use two classes of nonstop" printing mechanism, one in which the two sets of type cylinders are mounted on a common shaft and are suitable only for late news or edition headings, since with this arrangement it is possible only to employ printing plates which do not exceed one quarter of the circumference of the type cylinder, and the other, with which it is possible to employ printing plates which may extend over the full circumference of the type cylinders, having one set of said cylinders mounted on one shaft and the ot er set on another shaft. Both classes of mecha sm are open to certain disadvantages. Firstly, the mechanism embodies manually operated register clutches and changing from one set of type cylinders to the other is therefore dependent on the skill of the operator. Further, it is impossible properly to ink the surface of a set of type cylinders until after they have been laterally moved into contact with the impression cyilnder, and a considerable number of copies is therefore wasted upon each ammo? .moved for each change, one set into the operative position and the other into theinoperative position, two sets of operating gear being required to effect these changes.

In accordance with the invention a late news or like printing mechanism comprises an impression cylinder assembly and a pair of type cylinders arranged at opposite sides thereof, said impression cylinder assembly being movable into impression contact wtih either one or other of said type cylinders. The impression cylinder assembly may consist of a single impression cylinder movable laterally into engagement with either type cylinder, or a pair of impression cylinders which are movable together so that when one is in engagement with one of the type cylinders, the other is out of contact with the other type cylinder.

The shaft carrying the or each impression cylinder may for this purpose :be mounted in the front and rear press frame members in bearings which are movable through either a straight or arcuate path as by means, for example, of eccentrics, in a plane generally parallel to, but for convenience and design offset from, a plane through the axes of the type cylinders. Preferably the type cylinders are independently rotatable by means of gearing from the impression cylinder shaft and means are provided for synchronizing the surface speed of the inoperative type cylinder with that of the impression cylinder assembly before the latter is moved into contact with said type cylinder.

Referring now to the drawings, and more especially to Figure l, the impression cylinder assembly of a non-stop" late news or like printing mechanism includes an impression cylinder ID, with which are associated a pair of type cylinders designated II and I2 respectively. The type cylinders are laterally arranged at opposite sides of the impression cylinder so that either may be placed in operative driving engagement with contact with the other type cylinder, the bearings 2i are mounted in housings 22 which externally are of generally square contour and are carried by the front and rear press frame mem- :bers 23 within parallel elongated slots 24 therein. The shaft 20 is continuously driven from, for example, the main drive through a shaft 2! rotatable in a bearing 24 within a housing 21 secured to the rear press frame member 23. A

bevel gear 28 keyed on the shaft 28 meshes with a bevel gear 29 secured to a tubular stub shaft 30 Journalled on a bearing 3| within the housing 21 and substantially coaxial with the shaft 2. whenthe impression cylinder is out of engagement with both'of the type cylinders. The drive is transmitted from the stub shaft 30 to the shaft 20 through an Oldham" or other equivalent coupling 32 allowing relative displacement of the driving and driven axes, one of the outer members 33 of said coupling being secured to the stub shaft 30 and the other outer member 34 to the adjacent end of the impression cylinder shaft 20. The intermediate coupling member is designated by the numeral 35.

Secured to the stub shaft 30 for rotation therewith is a gear wheel 40 which is constantly in mesh with a pair of gear wheels 4|, 42, each of which is coaxial with one of a pair of shafts 43, 44 joumalled in bearings in the front and rear press frame members 23 and having keyed thereon the type cylinders ii, i2. The gearing 40, 4|, 42 constitutes a timing gear train of which the gears 41 and 42 rotate at the same angular speed as the type cylinders. The type" cylinder shafts 43, 44 are each adapted to be driven, in the extreme transverse positions of the impression cylinder, by means of a gear wheel 46 which is of slightly lesser pitch diameter than gear wheel 40, and is secured to the coupling member 34, said gear 48 in one position of the shaft 20 meshing with a gear wheel 41 secured to the shaft 43 and,

the impression cylinder while the other is in the inoperative position out of contact with the impression cylinder. 7

The type cylinder i2 is shown in the operative position and the cylinder II in the inoperative position, so that the paper web w, which pwses around substantially 180 of the impression cylinder to contact either type cylinder, receives the impression from the inked type matter on the type cylinder l2. As will be seen more clearly in Figure 1, the impression cylinder is offset in relation to a plane through the axes of the type cylinders. Figure 1 also illustrates the two sets of ink-distributing drums l3 and form-inking rollers i4,= i5 by which ink is delivered to the typecylinders, as well as a portion of a perfecting rotary press from which the newsprint is fed to the non-stop being out of driving engagement with the impression cy1inder,-is stationary and thus in readiness to receive any new type matter, such as a further late news item, which it may be desired to print.

Referring now to Figures 2 to 6 inclusive, the impression cylinder I0 is carried by a shaft 20 iournalled in bearings 2i and in order to enable the cylinder to be moved transversely from a position where, as shown in Figures 2a and 211, it is in printing engagement with one of the type cylinders. to a position where it is in printing unit. The type cylinder ll,,

in the other position of said shaft, with a gear wheel 48 secured to the shaft 44. The gear wheels 41, 48 are also of slightly lesser pitch diameter than the gear wheels 4|, 42, to provide the same gear ratio in relation to the gear 48 as that between the gear wheel 40 and the gears 4|, 42. Thus, when the impression cylinder is in engagement with the type cylinder l2, the latter is driven through the shaft 44 and the gear wheels 48, 48, the gear 46 being then out of engagement with the gear 41, while when the impression cylinder is in its other transverse position in engagement with the type cylinder .H, the latter is driven through the shaft lit-and gear 41 from the gear 46, said gear 46 being then disengaged from the gear 48. Accordingly while one of the type cylinders is in impression contact with the cylinder iii, the other is out of contact with said cylinder and, being stationary, is ready to receive any new type matter, such as late news, which it may be desired to print.

In addition to the gearing described above for driving the impression and type cylinders, each type cylinder shaft is coupled to one of a pair of electric motors 50, 5| mounted on the front press frame member 23. The purpose of each of these motors is to bring the respective type cylinder from stationary to printing speed before the impression cylinder is moved into engagement therewith. when a change is to be made in the matter being printed by one of the type cylinders,

- the motor associated with the then inoperative type cylinder, on which latter a plate containing the new matter has been inserted, is set in operation and, when this cylinder reaches a'speed approximately equal to that of the corresponding timing gear wheel 4| or 42, a pawl or dog 52 on said timing gear wheel engages a ratchet groove or recess 53 in the adjacent face of the corre-' sponding drive gear 41 or 48 and thus brings the speed of the type cylinder into registry with that of the timing gear wheel. The pawls 52 and grooves 53 also ensure that the type cylinders are in proper angular relationship to the impression cylinder before printing is commenced. As illustrated, each of the pawls 52 is pivotally mounted eccentrlcally of the axis of the corresponding timing gear wheel on a plate 54 secured to said gear wheel and is urged towards the ratchet groove in the corresponding driving gear wheel 41 or 48 by means of a. spring 55. The arrangement is preferably such that the pawl will lock within the ratchet groove immediately the driving gear wheel 41 or 48 commences to overrun the timing gear wheel 4| or 42 and will remain engaged in said groove until the driving gear wheel disengages from the gear wheel 46 and its speed thus drops.

A spring-loaded plunger 6| engages an enlarged portion am of the pawl to hold the latter against chattering until it engages within the groove 53.

In addition to synchronizing the speed of the inoperative type cylinder with that of the impression cylinder before these cylinders are brought into impression contact, engagement of the pawl or dog 52 as above described, within the recess in the corresponding driving gear wheel 41 or 48 may serve to control the movement of the impression cylinder and move it into engagement with the inoperative type cylinder to disengage it from the operative type cylinder, which by that time has been brought up to impression cylinder speed. For this purpose each of the driving gear wheels 41, 48 carries an electrical contact in the form of a spring-loaded push-button 66 (Figure 6) which is adapted to be engaged by the nose 6| of the pawl 52 when the latter enters and locks within the recess 53 in the corresponding driving gear wheel. This causes the push-button to be depressed to close an electrical circuit through a pair of contacts 62 on the driving gear wheel 41 or 48, a slip ring 63 and brushes 64 carried in a housing 65 secured on the rear press frame members around each type cylinder shaft ,43, 44, and conductors 66 leading from the contacts 62 to brush contacts on the slip rings. Each set of brushes 64 is connected in a control circuitof a reversible electric motor 10 which, through gear wheels H and I2, is coupled ,to a shaft 13 mounted for rotational and axial movement in bearing bushes 14 in housings 15 secured to the sides of 'the main press frame members 23, the shaft 13 being arranged parallel to the axis of the impression cylinder l0. Keyed on the shaft "at either end thereof is a worm 16, each of these worms being in driving engagement with a worm wheel 11 secured to a shaft 18 rotatably mounted in bushes in the corresponding housing 15. Also secured to each of the shafts 18 is an eccentric 18 which runs within a bore in a rectangular block 80 which, as shown in Figures 4A and 4B, slides within an elongated recess 88a in the associated bearing housing 22 within which the impression cylinder shaft 20 is mounted. Thus'upon energization of the motor 18, the eccentrics cause the bearing housings 22 to move within their slots 24 in the press frame members 23 and thereby move the impression cylinder laterally into surface contact with one or other of the type cylinon one of the worm wheels 11 is adapted to engage with one or other of a pair of adjustable stops 8!, 83, shown as comprising screws threadedin bosses in the corresponding housing 15, to limit the angular movement of the worm wheels 11 and therefore of the eccentrics I9 and, as will later be described, this cessation of rotation of the worm wheels is synchronized with the actuation of limit switches associated with and controlled by one of the worm wheels to de-energize the motor Ill and also the motor 58 or 5| by which the type cylinder now in impression contact with the cylinder It! has been brought to printing speed.

Although the motor 16 is cle-energizedwhen the impression cylinder engagesthe previously inoperative type cylinder, its rotor continues to revolve due to its inertia. As, however, rotational movement of the worm wheel 11 carrying the block 8| has been arrested by engagement of said block with one or other of the stops 82, 83, this continued rotation of the rotor of motor 10 will be translated into axial movement of the shaft 13. The shaft 13 continues to rotate, which at the same time ensures that rotation of the other worm wheel 11 ceases. This axial movement of the shaft 13 serves to compress one or other of a pair of springs 84 coiled about the shaft and each arranged between one of the worms l6 and a collar 85 loose on the shaft and engageable with a part of the housing 15 by which its axial movement on the shaft is limited. In each extreme axial position of the shaft 13 (in Figures 4A and 4B it is shown in the extreme left-hand position), this compression of one of the springs 84 maintains the lug 8| in engagement with the stop 82 or 83 by which rotation of the worm wheel 11 carryin said lug was arrested, while the other spring is relaxed. A pawl 86 pivotally carried on one of the housings l5 and movable into and out of engagement with the teeth of gear wheel 12 is provided to hold the impression cylinder in the required printing position. The pawl 86, as illustrated, is coupled to the armature 81 of a solenoid 8.8 which, as will hereinafter be described. is operable to hold the motor I0 stationary, thereby preventing displacement of the impression cylinder, until the then inoperative type cylinder reaches printing speed.

When a change is to be made in the printed matter and the motor 18 has been energized to rotate the shaft 13 in the reverse direction, the energ stored in the right-hand compressed spring 84 causes said shaft to move toward the right to a midway position where the two springs are balanced. Since during this axial movement of the shaft 13 the gears remain stationary, the motor is not under load and quickly reaches maximum speed so that, in the midway position of the shaft, the. motor has developed suflicient power to turnthe gears 11 and thus cause the impression cylinder to move into engagement with the other type cylinder. Thus the shaft 13, which is alternately spring-loaded in opposite directions, assists in quickly de veloping maximum power in the motor 10 to move the impression cylinder.

Figure 7 shows schematically the electrical equipment and connections by which the operation of the printing unit described above is controlled. This equipment includes, a manually operable main switch I88 and manually operable two-pole switches HH and J2 for connecting the motors 56 and 5| respectively into circuit to bring the corresponding type cylinders, 'as previously described, to approximately the surface speedof the impression cylinder, said switches IOI and III thereafter also controlling, in conjunction with the aforesaid contacts 52 and the pawl55, the operation of the motor 10 to change the position of the impression cylinder.

Assuming the press to be running and the impression cylinder of the non-stop printing unit to be in the position shown in Figures 1 to 5 of the drawings, 1. e. in printing engagement with the type cylinder I2, the circuit connections are as shown iri Figure 7, the switch I being open and the motors 50, I and de-energized. when it is desired to make a change in the matter printed on the paper web by the non-stop unit, a printing plate containing new or revised type matter is secured on the cylinder II and the switch I00 is closed. This completes a circuit from one side I03 of a direct current supply source, through a resistance I04 and back to the other side I05 of said current source. The switch IN is then actuated to complete a circuit from the line I03. through line I05, one contact I01 of the switch IOI, line I08, closed contact I00, oontactor coils H0 and III, and line II2, back to the other line I05 of the current source. Energization of the coils H0 and III closes a pair of triple-pole switches H3, H4, the former constituting an automatic contactor starter for the motor 50, and the switch II4 constituting an automatic contactor starter for the motor 10. The motor 50 is thus connected in the mains circuit I03, I05 to rotate the shaft 43 carrying the inoperative type cylinder II, while the motor 10 is held stationary by engagement of the pawl 85 with the gear 12, thereby preventing displacement of the impression cylinder until the type cylinder II reaches printing speed. A circuit is also established from the line I03, through line I I5, contact II5 of switch IOI, line II1, closed contact II5, lines I I9 and I20 and thence by way of a moving coil, centre zero voltmeter I2| and line I22 to the other side of the mains I05. The voltmeter, which includes two resistances I23 and I24, records the potential diiference between a fixed tapping I230 of the resistance I23 which governs the speed at which the change is to be made, and a variable tapping I240 of the resistance I24 the position of which varies in accordance with the speed of the press, beingconnected to a relay associated with the press-operating motor so that when the motor is energized the press is brought to the desired speed.

When the speeds of the type cylinder II and impression cylinder I0 have been brought into register and the pawl or dog 52 on the timing gear wheel 4i has engaged within the recess in the correspondingdriving gear 41 to close the contacts 52 through the push button 50, a circuit is completed fromthe line I03, through line II5, closed contact I25, contacts 52, line I25, coil I21 and line I25 to the resistance I04 and thence to the other line I05 of the supply mains. A single pole contactor gravity switch I25 is thus actuated to close a circuit from the line I03, through line I30, switch I25, line I3I, solenoid 55, and line I32 to the line I05.- Energization of the solenoid 55 causes the pawl 55 to disengage from the gear 12 thereby to permit rotation "of the motor 10 in a direction to move the impression cylinder laterally out of engagement with the type cylinder l2 and into engagement with the type cylinder II.

During the preceding operation of the press 1. e. with the impression cylinder in printing en- 52 associated with the driving gear 45 remained closed under the action 0! the corresponding pawl 52. However, immediately upon disconnection of the drive from the gear 45 to the gear 45 by movement of the impression cylinder to engage the type cylinder II, the speed of the shaft 44 drops and this pawl disengages from the co-operating ratchet groove 53 in the driving gear 45, with the result that the push button 55 of said driving gear is released and opens the corresponding contacts 52. Similarly the contacts 52 of the driving gear 41 will remain closed as long as the impression cylinder remallns in printing engagement with the type cylinder II,

When the impression cylinder reaches a position where it is in printing engagement with the type cylinder II, at which time the driving gear 45 is in mesh with the gear 41, the contacts I55, H8 and I29 are opened, in a manner to be described, the contact I03 releasing the switches H3 and M4 to de-energize the motors 55 and 15. Opening of the contact II5 disconnects the speed control voltmeter I2I and this permits variation of the speed of the press at the discretion of the operator. Finally, opening of the contact I25 enables the pawl 55 to reengage with the gear 12 to lock the motor 10 against rotation. The switch I00 is then actuated to break the supply circuit and the switch IOI, which is mechanically interlocked with the switch I00, is opened, this interlocking preventing subsequent operation of switch IOI until the switch I00 is again closed.

Simultaneously with the opening of the contacts I09, H8 and I23, three similar contacts I35, I36 and I31 associated with the motor II are closed. The contacts I35 and I35 are in circuit with the switch I02 which is also mechanically interlocked with the mains switch I00 and is therefore inoperable until said mains switch has been closed. The other switch I31 is in circuit with the contacts 52 of the gear 45, which contacts have been opened following disengagement of the driving gear 45 with said gear 45 and the consequent stopping of said latter gear. These contacts I35, I35 and I31 are therefore in the same positions as were the corresponding contacts I03. H5 and I25 during the preceding printing operation, 1. e. with the impression cyltinder2 in printing contact with the type cylin- The contact I35 is also in circuit with a pair of coils I35, I35 the formerof which controls the operation of a triple-pole switch I45 in the circuit of the motor 5i and the latter controlling the operation of a triple-pole switch I in the circuit of the motor 15 and through which said motor is energized to rotate in the reverse direction and thereby return the impression cylinder to the position shown in Figures 1 to 5. An electrical signalling or warning device such as a lamp, horn or bell, may be provided as shown at I42.

The two sets of switches I05, II5, I25 and I35, I35, I31 are each housed in a box I45, I45 respectively said boxes being hired on the housing 15 associated with the rear press frame member 23. These switches are arranged to be opened and closed mechanically and at the proper time; as by means of trip dogs (not shown) adiustabiy secured for rotation with the shafts 15. The setting of the abutment screws 52, 53 is synchronized with the angular positions of the dogs in relation to the respective sets of switches so that rotation of the worm wheels 11 and the shalt 13 is stopped immediately either switch has been gagement with the type cylinder I2, the contacts actuated.

Despite the provision of means for synchronizing the speed of each type cylinder with that of the impression cylinder before moving the latter out of impression engagement with one type cylinder and into impression engagement with the other, it is necessary that the driving gear wheel 46 shall engage the gears 41 and 48 without jamming. With this in mind the teeth of these gears are cut on the addendum to a point and each of the isosceles angles formed by the intersection of planes through the axes of the type and impression cylinders-the axis of the impression cylinder being offset from a plane through the axes of the type cylindersis less than the pressure angle of the wheel teeth.

Figures .8 and 9 illustrate a. modified arrangement in which, instead of the parallel sliding bearing housings 22 for the impression cylinder shaft as shown in Figures 1 to 5, annular eccentric bearing housings I50 are provided, there being on such housing at each end of said shaft arranged within circular openings in the correspondin end press frame members 23'. Each bearing housing I50 has attached thereto a quadrant gear I 5I'meshing with one of a pair of helical gears I52 at opposite ends of the shaft 13. The shaft 13' is driven from the motor which in this embodiment has its axis normal to that of the shaft 13', through a worm I53 on the motor spindle and a worm wheel I54 on said shaft. The motor shaft also has secured thereto a ratchet gear I55 with which the locking pawl 86 is adapted to engage under control of the solenoid 88.

With this modified form of bearing housing for the impression cylinder shaft, the trip dogs for actuating the two sets of limit switches I09, II8, I25 and I35; I36, I31 of the electrical equipment are secured to one of the bearing housings I50 for rotation therewith. Figure 9 shows one of the switch boxes I45, I46, the switches being of the toggle kind having a pair of coaxially arranged pivoted arms I90, I9I respectively engageable with trip dogs I92, I93 mounted on one of the rotatable bearing housings. The trip dogs are angularly adjustable on the bearing housing as by means of a slot and bolt connection so that their positions maybe varied in accordance with the setting of the abutment stop screw 02, 83.

This modified arrangement, due to the bearings being supported around their entire peripheries by solid metal of the end press frame members, enables the impression cylinder to with- I stand heavier loads, such as when printing from' pages 'oftext or half tones, without variation in the quality of the printed matter. Although the path of movement of the impression cylinder While it is being changed from one printing position to the other will be arcuate instead of straight, as in the-embodiment of Figures 2 to 5, thereby resulting in stretching of the paper web, the increase in tension may have no serious effect on the printing, being limited to'a few ounces per inch of web.

Figure 10 shows an alternative arrangement of the mechanism and electrical equipment for controlling the operation of the solenoid 88. The contacts 62 and pushbutton 60 are here replaced by a switch I60 secured on the gear housing 21' of the rear prrss frame member 23, each switch having a pair of contactsinot shown) correspondingto the pair of contacts 62 carried by the driving gears 41' or 48. Each pair of contacts is adapted to be actuated to open and close the solenoid control circuit through the; coil I21 manner as in the arrangement of Figures 8 and 9,

by a rod I6I which is arrangedfor axial movement within the stud of the corresponding timing wheel M or 42'. The inner end of the rod I6I is pivotally connected at I63 to an arm I64 which is secured to the pawl 52 for rocking movement about the pivotal axis thereof. This arrangement has the advantage that the electrical equipmentis entirely separate from the mechanical so that when dismantling or adjusting any of the mechanical components there will be no danger from live connections.

In Figures 11 and 12, the impression cylinder assembly of a late news or like printing mechanism comprises a pair of impression cylinders I10, I'll each of which is movable into and out of printing engagement with one of a pair of type cylinders I12, I13. The type cylinders are mounted and driven in the same manner as the cylinders II, I2 of Figures 2 to 5. Each of the impression cylinder shafts I14, I15 is driven from a main drive shaft I16 to which are secured two bevel gears I11, I10 meshing with a pair of bevel gears I19, I on the respective impression cylinder shafts. The latter are shown as being carried at each end in eccentric bearings I8I in the same and each bearing has secured thereto a toothed quadrant I82 which is in mesh with one of a pair of helical gears I820 secured at opposite ends of a shaft I83, similar to the shaft 13 and driven from the motor 10 in the same manner as in Figures 8 and 9. Each cylinder shaft, furthermore, is driven through a coupling I84 or I85 similar to that shown in the first embodiment.

It will be clear from Figures 11 and 12 that as the eccentricv bearings supporting the respective impression cylinder shafts are arranged so that while one of said cylinders is in impression engagement with the corresponding type cylinder, the other impression cylinder is out of engagement with the other type cylinder, the latter therefore being stationary, rotation of the shaft I83 will cause simultaneous angular movement of the quadrants to move the impression cylinder assembly to its other operative position. Both impression cylinders are continuously driven and the paper web 20 passes about both cylinders in turn, in this arrangement, however, engaging only about f of each cylinder surface.

Self-synchronous motors may be employed in place of the motors 50 and 5| to bring the respective type cylinders to printing speed. Where motors of this kind are employed, the timing gear train 40, 4|, 42, the pawls 52 and the contacts 62 or switch I60 are unnecessary.

The mechanism described in each of the aforesaid embodiments willbe seen to be entirely automatic in operation and, being independent of register clutches, is also independent of the skill of the operator. Since only one cylinder assembly is required to move in order to make a change in the matter printed on the web, only one operating mechanism is required. Further the invention enables printing plates of full or partial circumferential length to be used. Finally, as the type cylinders remain stationary, the invention avoids any difliculties in supplying ink thereto, with the result that the inoperative type cylinder may be effectively inked before it is placed in impression-contact with the paper web.

What I claim and desire to secure by Letters Patent in the United States is:

1. A late news or like printing machine comprising an impression cylinder, a pair of laterally spaced tyPecylindera-means for driving the imaeasne'r pression' cylinder, means for rotating the type cylinders independently of the impression cylinder and for synchronizing the surface speeds of the impression and type cylinders, means for automatically moving said impression cylinder laterally into impression engagement with one or other of said type cylinders and control means actuated when the surface speed of the latter is synchronized with that of the impression cylinder for initiating movement of said automatically moving means, and means thereafter for drivins the operative type cylinder from the impression cylinder. 7

2. A late news or like printing mechanism comprising an impressioncylinder, a pair of laterally spaced type cylinders, a hollow drive shaft, a coupling for drivingthe impression cylinder from said drive shaft, means for driving either of the type cylinders independently of the impression cylinder, a driving gear rotatable with the impression cylinder and engageable with one or other of a pair of driven gears for driving each type cylinder from said impression cylinder, a timing gear train including a driving gear on said hollow drive shaft and a pair of driven gears coaxial with the type cylinders, a dog on each of said driven timing gears engageable within a recess in the corresponding driven type cylinder gear when the surface speed of each type cylinder reaches that of the impression cylinder, means controlled by each of said dogs for disconnecting the independent type cylinder driving means, and means for simultaneously moving the impression cylinder laterally out of engagement with one of said type cylinders and into engagement with the other of said cylinders.

3. A late news or like printing mechanism comprising an impression cylinder, a pair of laterally spaced type cylinders, a hollow drive shaft, a coupling, for driving the impression cylinder from said drive shaft, an electric motor for driving each type cylinder independently of the impression cylinder, a driving ge. r rotatable with the impression cylinder and engageable with one or other of a pair of driven gears for driving each type cylinder from said impression cylinder, a timing gear train including a driving gear on said hollow drive shaft and a pair of driven gears coaxial with the type cylinders, a dog on each of said driven timing gears engageable within a recess in the corresponding driven type cylinder gear when the surface speed of each type cylinder reaches that of the impression cylinder, electrical connections in each motor circuit actuable on engagement of the corresponding dog within the recess in the associated type cylinder driving sear to stop said motor, and a reversible electric motor for moving the impression cylinder laterally out of engagement with one of said type cylinders and into engagement with the other of said cylinders.

4. A late news or like printing mechanism comprising an impression cylinder, a type cylinder at one side of said impression cylinder, means for driving the type cylinder independently of the impression cylinder and for synchronizing the surface speeds of said impression and type cylinders, a frame, bearings in said frame supporting the impression cylinder, an eccentric connected to each of said bearings, and a reversible electric motor for actuating said eccentrics to move said bearings laterally of the frame thereby to place said impression cylinder in impression engagement with said type cylinder and means for energizing said motor when the surface speed of the 12 latter is synchronized with that of the impression cylinder.

5. A late news or like printing machine comprising an impression cylinder, a pair of type cylinders at opposite sides of said impression cylinder, means for driving each type cylinder independently of the impression cylinder and for synchronizing the surface speeds of said impression and type cylinders, a frame, eccentric bearings in said frame supporting the impression cylinder, a reversible electric motor for rotating said bearings thereby to move said impression cylinder laterally into impression engagement with one or other of said type cylinders when the surface speed of the latter is synchronized with that of the impression cylinder, a detent operating on said rotating motor to prevent rotation of said bearings and means actuated by rotation of said bearings for actuating said detent to prevent further rotation'of said bearings.

6. A late news or like printing machine comprising an impression cylinder, a pair of laterally spaced type cylinders, means for driving the impression cylinder, means for rotating the type cylinders independently of. the impression cylinder and for synchronizing the surface speeds of the impression and type cylinders, motor means for moving the impression cylinder laterally out of printing engagement with one and into printing engagement with the other of said type cylinders, control means for said motor actuated when the speed of said latter type cylinder is synchronized with that of said impression cylinder, and means for then driving said type cylinder from the impression cylinder.

7. A late news or like printing mechanism comprising an impression cylinder, a pair of laterally spaced type cylinders, means for rotating the impression cylinder, an electric motor for bringing each of said type cylinders to the surface speed of the impression cylinder, a reversible electric motor for moving the impression cylinder laterally out of engagement with one type cylinder and into engagement with the other, pawl and ratchet mechanism for locking said impression cylinder against such lateral movement until the surface speed of the inoperative type cylinder is synchronized with that of the impression cylinder, and a solenoid energizable upon synchronization of said speeds to release said locking mechanism.

8. A late news or like printing mechanism comprising an impression cylinder, a pair of laterally spaced type cylinders, means for rotating the impression cylinder, electric motors for rotating the type cylinders independently of the impression cylinder, means for synchronizing the surface speeds of the impression and type cylinders, a reversible electric motor operable upon synchronization of said surface speeds for moving the impression cylinder laterally out of engagement with one type cylinder and into engagement with the other, mechanical means driven by said reversible motor for automatically stopping said motor and the type cylinder driving motor upon completion of the lateral movement of the impression cylinder, and means operable in such position of the impression cylinder for driving the operative type cylinder from said impression cylinder.

9. A late news or like printing mechanism comprising an impression cylinder, a pair of type cylinders at opposite sides of the impression cylinder, means for rotating the impression cylinder, electric motors for rotating the type cylinders independently of the impression cylinder, means for synchronizing the surface speeds of the impres- 

